Pre-harvest application of a new biocontrol formulation induces resistance to post-harvest anthracnose and enhances fruit yield in mango

Pre-harvest application of biocontrol formulations consisting of 1. the two plant growth promoting rhizobacterial strains FP7 and Pf1 of Pseudomonas fluorescens; 2. a strain of Bacillus subtilis Bs-1; and 3. a strain (Sc-1) of the yeast Saccharomyces cerevisiae, given at fortnightly or monthly intervals and with or without a chitin amendment, were evaluated in two trials for their ability to reduce anthracnose in mango caused by Colletotrichum gloeosporioides. Growth of C. gloeosporioides in vitro was significantly reduced by strain FP7 and in both field trials the bacterial strain in combination with chitin significantly reduced infection. Pre-harvest application of these formulations at fortnightly intervals also significantly improved flower initiation, yield parameters (mean number of fruits and fruit yield) and fruit quality (total soluble solids, ascorbic acid, free acidity, total, reducing and non-reducing sugar content). The delay in latent symptom expression increased by 15 days under stored conditions. The highest levels of phenolic content, peroxidase and polyphenol oxidase on mango leaves, flowers and fruits were achieved with FP7 +chitin.